title: Modulation of early β-defensin-2 production as a mechanism developed by type I Toxoplasma gondii to evade human intestinal immunity.
abstract: We investigated the early innate immune responses induced in human intestinal epithelial cells (IEC) by the three defined Toxoplasma gondii genotype strains. Transcriptome analysis revealed that among differentially expressed genes, β-defensins distinguished the most IEC infected by fast- or slow-replicating T. gondii genotypes. Although β-defensin 1 and 3 genes were not expressed in host cells at early time points postinfection, the slow-replicating type II and III parasites induced high levels of β-defensin 2 gene expression. Notably, no β-defensin 2 gene expression occurred early after infection with the fast-replicating type I parasite. However, activation of this gene in IEC by poly(I:C) treatment prior to infection substantially decreased parasite viability, and pretreatment of parasites with synthetic β-defensin 2 significantly reduced their infectivity of IEC. These findings strongly support the modulation of early β-defensin 2 expression as a mechanism used by type I T. gondii parasites to mediate immune evasion.
authors.affiliation: Toxoplasmosis Laboratory, Operational Direction Communicable and Infectious Diseases, Scientific Institute of Public Health, 1180 Brussels, Belgium.
authors.forename: Vijay
authors.initials: V
authors.lastname: Morampudi
authors.forename: Michel Y
authors.initials: MY
authors.lastname: Braun
authors.forename: Sushila
authors.initials: S
authors.lastname: D'Souza
mesh_terms: D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D057131:Immune Evasion / Q000276:immunology*; D018928:Immunity, Mucosal / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014122:Toxoplasma / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity; D014123:Toxoplasmosis / Q000276:immunology* / Q000378:metabolism; D023083:beta-Defensins / Q000096:biosynthesis* / Q000276:immunology
chemical_list: C106641:DEFB4A protein, human; D023083:beta-Defensins